Drilling jig for angle irons



c. B. LUBBERT DRILLING JIG FOR ANGLE IRONS Filed Nov. 4, 1947 Aug. 21, 1951 f v \NN v fi R 1w J Kiwi kw a 1 =1 &

A 7" TORNEV INVENTQR C. B LUBBERT Patented Aug. 21 1951 DRILLING JIG FOR ANGLE IRON S Carl B. Lubbert, Anneslie, McL, assignor to Western Electric Company, incorporated, New York, N. Y., a corporation of New York Application November 4, 1947, Serial No. 783,964

1 Claim. 1

This invention relates to fixtures for holding elongated articles during drilling operations, and more particularly to drill jigs for angle irons.

' In the manufacture of communications equipment, angle irons are used extensively in the fabrication of frames on which the various types of apparatus are mounted. An angle iron frame includes a plurality of angle. irons of various lengths arranged to form the desired shape of the framework. At least some of the. angle irons must be provided with suitable holes for securing the angle irons together and also for mounting apparatus on the frame. In order to facilitate rapid manufacture of such angle iron frames, the individual members of the frame are processed in substantially large quantities. Those members in which a plurality of holes are to be drilled in accordance with a predetermined pattern require a suitable fixture or drill jig for holding the angle iron during the drilling operation and for eifecting a rapid transfer of a plurality of holes from a given template or pattern to the angle iron.

The fixture must be arranged to support the angle iron so that the leg thereof in which the holes are to be drilled is substantially horizontal with respect to the work table of the machine performing the drilling operation and must permit easy insertion and removal of the angle iron.

In the past fixtures for holding angle irons have been arranged so that the angle iron must be slid longitudinally into the fixture. In areas' where the working space allowed for performing the drilling operation on such elongated angle irons is limited, the fixture must be arranged so that the angle iron may be inserted lengthwise into the fixture.

An object of the invention is to provide new and improved fixtures for holding angle irons during drilling operations thereon.

A drill jig for holding angle irons embodying certain features of the invention comprises an elongated template having a predetermined drilling pattern provided therein, means for supporting the template in a horizontal position, and means for clamping an angle iron to be drilled in the template, whereby the drilling plan of the template may be transferred to the angle iron clamped therein.

A clear understanding of the invention will be had from the following detailed description of a specific embodiment thereof, when read in conjunction with the appended drawing, in which:

' l9i3 (Figs. 1 and 2) spacedly positioned on an elongated template ll having a right angle cross section, as seen in Fig. 3. Each of the supports Iii-Ii is provided with clamping means indicated generally at l2-|2 for clamping an elongated angle iron l3 against the corresponding inner surfaces of the template H. The supports Iii-40 and their respective clamping means l2l2 are identical in construction and operation. Therefore, the following description will be directed only to the support Ifl shown in the upper left hand corner of Fig. 1, a cross sectional view of which is shown in Fig. 3.

The U-shaped support H] consists of an upper horizontal leg It, a lower horizontal leg I5 spaced a predetermined distance apart and parallel to each other by a vertical leg 16 which is rigidly secured to one end of each of the legs 14 and IS. The composite U-shaped supports l0|0 are secured to the template II by conventional machine screws Il-l'l.

The clamping means l2 provided on the U- shaped support It comprises an arm 2| pivotally mounted at one end thereof in a slot 22 provided in the leg i5 of the support H] by means of a pin 23 positioned in a bore 24 provided in the portions of the leg I 5 adjacent to the slot 22. A latch bolt 25 has one end thereof pivotally mounted in a slot 26 provided in the free end of the arm 2| by a pin 21 positioned in a bore 28 provided in the portions of the end of the arm 2| adjacent to the slot 26. The leg Hi of the support I!) is provided with a slot 30 for receiving the free end of the bolt 25 when it' is positioned vertically, as shown in Fig. 3. The free end of the bolt 25 is threaded to receive a conventional wing nut 3| by means of which the arm 2! may be raised or lowered as desired.

The arm 2| is provided with a tapered bore 33 to receive in a relatively loose manner a body portion 34 of a stud 35. An irregularly shaped nut 36 is threadedly mounted on a threaded end 3'! of the stud 35 until the face thereof abuts a shoulder 38 formed at the junction point of the body 34 and the threaded end 31. The, length of the body portion 34 of the stud 35 is slightly greater than the thickness of the arm 2I so that when the nut 36 is screwed tightly against the shoulder 38, substantial play exists between the nut and the inner face of the arm 2I and between the head of the stud 35 and the outer face of the arm.

The nut 36 is provided with a pair of accurately machined surfaces at substantially 90 with respect to each other, which machined surfaces are arranged to engage the inner surface of the op-' posite legs of an angle iron, such as the angle iron I3, which is to be clamped in the template I I. A pin 39 is secured in the arm2I so as to loosely engage a recess 40 provided in the face ofthe nut adjacent to the inner face of the arm. This arrangement prevents the nut from turning with respect to the arm 2I and at the same time provides for a rocking movement of the body 34 of the stud within the bore33. The ability of the stud 35to rock within the tapered bore 33 permits the nut 36 to 'seat'itself against the inner legs of the angle iron I3 against which it is to be clamped by means of the arm 2 I, the bolt 25 and the wing nut 3I. By loosening the wing nut 3I the bolt may be withdrawn from the slot 39 provided in the leg ll of the support I so that the arm 2I of the clamp I2 may 'be lowered to a substantially horizontal position shown by broken lines in Fig. 3. When the arm 2| is in its lowered position the angle iron 13" may be readily inserted in or removed from the template I'I A'pin 4| is positioned adjacent to the left end of the template N (Fig. 1) to engage the left end of the angle ironl3 and acts as a stop in loeating the angle iron I3 'in' the template I I. Inadditiorf to the pin 4|, pins 42 and 46 (Fig. 3) are provided in the template to properly orientate the legs of the angle iron I3 in the template II when the holes to -be drilled in the angle iron must be'ar a definite relationship not only to a particular end of the angle iron but also to certain holes which have been previously located in the legs 'of the-angle iron. The pins M, 42 and 46 serve to locate the angle iron I3 in a predetermined position in the template I iwith respect to a'plurality of drill bushings43-43 positioned in the-horizontal'leg of the template II atpoints A, B, C, D, E; and F, inaccordance'with a predetermined drilling plan or pattern.

The drill bushings 43-4'3'serve to locate a conventional drill'44 positioned in a chuck 45 of a conventional drill press (not'shown) so that holes maybe drilled in the angle iron I3 at points'A, B, C,-D. E and F, respectively. In other words, the bushings 43-43 serve as means of transferring the hole pattern of the template I I as determined by'the location of the drill bushings therein to the angle iron I3 clamped in the template by the clamps I 2-I2. A plurality of hardened. steel feet 41-41 are secured on each of the supports I' Il-III so as to locate'the horizontal leg of the template II in which the drill bushings 43-43 arepgsitioned parallel to a work table 48 associated with the conventional drill press of which only the drill 44 and the chuck 45 are included in eedre i miien The above-described apparatus operates in the following manner:

Let it be assumed that the composite drilling fixture comprising the supports I'D-I0, the template -II and the clamping members I2-I2 is positioned on the work table 48 of a conventional drill press (not shown) which is to perform the drilling operations. Each of the clamps I2-I2 mounted on the supports Ifl-IO are placed in their open or lowered position, in which position the arms 2I-2I assume a substantially horizontal position, as shown in Fig. 3. An angle iron, such as the angle iron I3, to be drilled in accordance with the location of' the drill bushings positioned in the template II is placed in the template so that the left end of the angle iron engages the pin M and the pins 42 and 46 engage indexing holes provided in the opposite legs of the angle iron. Since the indexing pins 42 and 46 are of different diameters, it is possible to position the angle iron in the fixture in only one position.

After the angle iron has been properly positioned in the template I I, the arms 2 I-2I forming part of their clamping means I2-I 2 are positioned in an oblique position by positioning the bolts 25-25 in their respective slots 30-30 of the'supports IIl-Iil. This places the nuts 36 -36 movablysecurd on the arms in position to engage the'inner surfaces of the legs of the angle iron I3. Each of the wing nuts 3I-3I are now turned in a" direction which will draw its associated arm 2I upwardly and thereby urge the nut carried thereby tightly against the legs of the angle iron I3. The particular arrangement of the arm 2I and the nut 36 secured thereon is such that a two-directional t hrust is directed against the angle iron when the wing nut 3I is turned in a direction to draw the free end of the arm 2| upwardly. This two-directional thrust imparted against the angle iron serves to simultaneously urge the angle iron upwardly against the horizontal leg of the tem-' plate II and rearwardly against the vertical leg of the template I'I.

After each of the clamping means I2-I2 has been operated in this manner, the fixture is moved o'ri'the work table 43 until the drill bushing 43 located'at point is directly under the drill 44. With the fixtureinthis position the drill is lowered into the bore provided in the bushing and into engagement with the leg'of the angle iron and positioned immediately below the drill bushing 43. Continuedmovement of the drill 44 will drill 'a hole in the angle iron I3 at point A. By'

successively positioning the drill bushings 43-43 located at points B, C, D, E and F in the template II" under the drill 44, holes may be drilled in the angle iron I3 at these points whereby the complete drill pattern'of the template is transferred to the leg'of'tlie angle iron I3. When thedrilling operation on the angle iron I3 'is complete, it is only necessary to'turn the wing nuts of their'respective clampingmeans a few turns and lower the arms 2I"-"-"-2I to their open position in order to be able to remove the drilled angle iron I'3 from the fixtureand insert another angle iron therein.

' It will be noted that this type of drilling fixture for angle irons does not require that the angle iron be slid longitudinally into the fixture from one end thereof; which operation would require a working space approximately twice as long as the angle iron itself. Where the angle iron is of substantial length, it is believed to be apparent that the working space required to load a fixture from one end thereof would seriously hamper the use of such fixtures in factories where only limited working space is available. 'The above-described fixture can be loaded and unloaded in the space required for handling the particular angle iron involved.

While the above-described fixture is illustrated as having the drill bushings located only on the horizontal leg of the template H, it is believed to be apparent that suitable feet may be inserted on the ends of the horizontal legs '[4 and I5 of the U-shaped supports l0l 0 which would facilitate positioning the fixture on the work table 48 so that the vertical leg I6 and the opposite leg of the angle iron 13 wouid now be in a horizontal position with respect to the work table 48. With the fixture in this position, holes could be drilled in the opposite leg of the angle iron IS in accordance with any desired drilling plan.

What is claimed is:

A fixture for holding elongated angle iron members during drilling operations, which comprises an elongated member of right angle crosssection in which an angle iron member to be drilled may be positioned, a plurality of drillguide bushings positioned in the member in accordance with a predetermined drilling pattern, a plurality of U-shaped supports secured spacedly on the member in such a position that the parallel legs of said supports are parallel to one of the legs of the member, means provided in the member for orienting the respective legs of the angle iron to be drilled with respect to the dril1 bushings in the member, an arm mounted pivotally on one of the legs of each of the U-shaped supports, a bolt mounted pivotally on the free end of each of the arms and arranged to engage slots provided in the opposite legs of the U-shaped supports, a wing nut threadedly mounted on the free end of each of the bolts for holding the arms in an oblique position with respect to the right angle legs of the member, and a lug loosely mounted CARL B. LUBBERT.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,579,284 Grotto Apr. 6, 1926 2,342,059 Moss Feb. 15, 1944 2,367,582 Honyoust Jan. 16, 1945 2,389,184 Cooke Nov. 20, 1945 2,438,162 Guest Mar. 23, 1948 FOREIGN PATENTS Number Country Date 603,023 Germany Sept. 21, 1934 OTHER REFERENCES Oberg and Jones Text Drilling Practice and Jig Design (1915), pages 203 and 204, published by Industrial Press, New York. (Copy to be found in Div. 13.) 

